On the prime graphs of the automorphism groups of sporadic simple groups

Behrooz Khosravi

Address: Department of Pure Mathematics, Faculty of Mathematics and Computer Sciences Amirkabir University of Technology (Tehran Polytechnic) 424, Hafez Ave., Tehran 15914, Iran & School of Mathematics, Institute for Research in Fundamental Sciences (IPM) P. O. Box: 19395-5746, Tehran, Iran

E-mail: khosravibbb@yahoo.com

Abstract: In this paper as the main result, we determine finite groups with the same prime graph as the automorphism group of a sporadic simple group, except $J_2$.

AMSclassification: primary 20D08; secondary 20D60, 20D05.

Keywords: automorphism group of a sporadic simple group, prime graph.